Electric indicator



F. W. WOOD.

ELECTRIC INDICATOR. APPLICATION FILED AUG. 7. 1919,

1,396,803, Patented NOV. 15, i921. 39

JQML f@ ATTORNEY UNlTEDsTA-rss PATENT orrlca'l FRANK W. WOOD, 0F MONTCLAIR, NEW JERSEY, ASSIGNOR TUCHAIRLES CORY SON, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION 0F NEW YORK.

ELECTRIC INDICATOR.

Specification of Letters Patent.

Patented Nov. 151921.

Application mea August 7, 1519. serial No. 316.003.

To all whom it may concern Be it known that I, FRANK W. Woon, a citizen ofthe nited States, residing at Montclair, in the county of Essex and State of New J ersey, havefinvented .new and useful Improvements in Electric Indicators, of which the following is a specification.

My invention relates to electricindicator systems for transmitting signals and particularly to a receiver for such a system carrying indicating means positioned b v the energizing of magnetic element-s .in the receiver.

e Systems of this kind generally consist of a transmitter and a receiver, the transmitter including a rotating indicator, and the receiver having a similar indicator which follows the motion of the transmitting indicator and shovvs the position thereof. Systems of this kind are particularly adapted for transmitting signals. orders` or other information either b v means of dial and pointer or similar rotating indicating means, the position of the dial or pointer of the transmitter being reproduce v on the dial or pointer of the receiver. Such systems are particularly used on ship board for the purpose, for instance` of indicating the course of the vessel, `the number of revolutions per minute of the. engine shaft` the angular position of a torpedo gyroscope, the angle of the rudder, or`to` transmit orders from central control stations.

My invention relates particularly to a receiver for a. system ofl this kind, my receiver being of the mot-or type having a stator composed of a plurality' of ield magnets each having a pole piece. a rotor inside the stator preferably having a plurality of magnets, eac-h having a f`pole piece which cooperates vvith those of the stator to form magnetic circuits, the magnets being so arranged that -the energizing of selected'field magnets vvill definitely position the rotor through balancing ofmagnetic forces, and will correspondingly ix the position of an indicating element such as a ydial or pointer carried by the rotor shaft. VThe transmitter may be of the type shown in Patent No. 1.100.860 granted Ato me on June 23, 1914, in which a rotating contact arm coperates with suitable contacts thereabout to energize selected field magnets. the magnets which are energized beingdetermined by the position of the contact arm which carries an 1ndic'ating element similar tothat on the transmitter. It will be seen that by` a proper arrangement such as that indicated in the above patent. the position of the transmitter indicator `vvill be exactly duplicated by the receivei` indicator.

An object of my invention is to arrange and construct the receiver so that a- -larger number of positions for the indicators may be obtained with the same number of field magnets..I In the construction of the patent, for instance, five field magnets arensed to produce ten indicator positions, While in my construction` the same number of field magnets will. locate the indicator .in 20 different positions. The transmitter is not shown or described herein, as it forms no part of my invention and may be ofany desired form or type. A

I have so constructed my receiver that I may locate all the pole pieces at one end of the magnet structure, Where they are readily accessible` instead of having them substantially in the middle thereof. Furthermore, I have utilized a single set of pole pieces on the field magnets and have eliminated'the use of coaxial pairs of magnets, thus .reducing the cost of the construction and increasing the. simplicity and efficiency of the indi- Icator. I havemounted my entire struct-ure upon, so as to be readily detachable from. its base. which also carries the electric connections,^facilitating the repair and adjust-- ment of the unit Without disturbing' its mounting or disconnecting circuits from the mounting; I have also provided rotor l'pole pieces ofi-improved construction having a series of salient poles which facilitate the accurate and quick location of the rotor in exact position, the pole pieces having faces.

long enough to lie opposite adjacent field magnets poles` rendering the rotor readily responsive to changes in the magnetic field.

Further objects and advantages of my invention will be apparent from the following description taken in connection vvith the accompanyingdrawings, in which:

Figure 1 is a longitudinal cross-sectional view of the indicator,

Fig. 2 is a bottom plan view with the base structure broken away.l

Fig. 3 is a top plan view. part being broken away, and 1 Fig. 4 is a- Wiring diagram.

The indicator includes a plurality of field five in'number letteredfrorn A to E inclu' sive; but it will be apparent that my inven- 5 tion is equally applicable to any selected y number of field magnets. Each of these magnets consists of the usual winding's`10 about a core 11 which is mounted on an annular plate 12 as by screw 13. At 4the opposite end of the magnet from plate 12 and preferably adjacent the base of the indicator,

is mounted pole piece 14. The magnets are mounted on carrier plate 15 by means of screws passing therefrom into the cores of 15 the magnets Carrier plate 15, which vcarries the entire indicator mechanism, is adapt- .).edto be'removably mounted upon base 16 by means of screws, said base carrying a plurality of cont-act studs 17, each mounted in a L cylindrical holder 18 in the base, a spring 19in each holder serving to pressthe stu outwardly. A contact rod 20 is mounted in the rear end of each field magnet, andconnected to one end of vthe winding thereof,

passing through a suitableinsulating block 21 in carier plate .15 and being located so as to press against contact stud 17 when plate 15 1s in position with base 16. LAiposition- .ing stud 22 may be mounted in the base registered with a "suitable aperturein carrier plate 15, facilitating the positioning of the carrier plate accurately on the base whenmounti'ng the indicator. It will be apparent thatthis construction makes it posslble to permanently fix the base in the desired location and to connect the holders 18 with the proper circuits, the magnets being connected to the circuits and the "indicator mounted in position by`merely fixing carrier plate 15 upon the base, lthe carrier plate and its.

mechanism being readily detachable'for repairs without deranging the base or its connections. v

' The rotor consists of two magnets, each having a. pole piece coperating with `the stator pole pieces. The rotor magnets may be yconstructed and arranged in vari'ou's Ways@ I have shown them as composed of two Sep! arate windings 23 ,and 24 mounted` side by side upon a .plate 25" to which they are attached as by screws 26. At the. opposite end, the rotor magnets carry polev pieces 27 and 28 and are mounted upon plate l29 overlying 'the pole pleces, the parts being fixed in p0- sitlon 1 n any desired manner as by screws passing through the plate 29 and the pole pieces 1nto.. the cores'of the'rotor magnets 23 and 24. Plate 29 has an annular cen- -trally projecting stud 31 which revolves in an aperture 32 in carrier-plate 15, forming a bearing for one end ofthe rotor. Plate 25 at the opposite end of the rotor has mounted thereon a short -shaft 33 revolving. in a bearing in spider`34 which is mounted on annular plate 12. Between spider 34 and I plate 25, collector ri\ 35 and 36 are mounted on a block of ins lation 37 on shaft 33.'

Each collector ring is in. contact with an insuljgd sprin spider 34. he outer end yof.shaft 33 is extended through the spider and carries suitable'indicating means, such, for instance, as dial 39.,

Pole pieces 27 and 28 are formed along their outer faces into. a series of salient\poles 40 concentrically arranged about the axis The distance beof rotation of the rotor.

pressed brush 38 carried by` tween salient poles is an integral part of the length of the ad'acent faceof field magnet pole piece 14. referably the distance between adjacent 'salient poles 40 is equal to half the width of the face of pole piece 14. The distancesbetween the faces of adjacent field magnet pole pieces is, in this-case,

equal to the "width of each face. With this construction, it will be seen that when the rotor revolves through an angle equal to one quarter of theangular distance between centers of adjacent field magnets, the 'salient poles` of the rotorpole pieces will lie either exactly inthe middle or at the extreme endsof the field magnet pole pieces and .1t will be apparent that this construction: facilitates Q the positive accurate location of the pole pieces in fixed position when the circuits are suitably'energized. lVhile I have shown the rotor pole pieces as having seven poles, it is obvious that this number may be varied so long as the fundamental relatlon between the spacing of thesalient poles, the Width of the field magnet pole pieces and the distance between' adjacent field magnet pole pieces is maintained.

I have shown in Fig. 4 one methodof arranging the electrical circuits in my receiver. By this method, each field magnet is wound in the same direction so that a current passing through the magnetsfrom roo top'to bottom would produce the same polar- 'ity in each. I prefer to connect the-corre-' sponding end of each winding to a common connector such as wire 41, as shown in Fig. 3. The opposite end ofeach field magnet winding is connected to the transmitter which coperates tov energize proper field magnets so as to position the rotor in respect thereto. VThe rotor magnets 23 and 24 are wound in opposite directions so that pole pieces 27 and 28' are of opposite polarity, the magnets being connected vin series and having the opposite ends of their respective windings connected'to collector rings 35 and 36 which are connected through brushes 38 with the opposite poles of the source of elec; trica'l energy. Obviously, the method of arranging and energizing the rotor magnets may be varied considerably; but in any event, it is desirable that they maintain perthe same manner as is disclosed in my application No. 262,313, filed November, 1918 and maybe operated by any suitable form of transmitter such 'as the one shown in said application,- or any suitable adaptation of the transiiiit-ter shown and described in my above mentioned patent. By suitably energizing selected field magnets, the rotor may have twenty different positions if five field magnetsare used. each pole piece being positivelyv located either directly opposite a field magnet pole piece or in any one of three equally spaced positions between adjacent field magnet pole pieces. By properly operating a suitable transmitter, the receiver Vindicator may be moved by a step step motion. consisting of twent-y steps in completing a full revolution: but it is to b e understood that each position of the indicator is entirely independent of its previous position. and that my construction is. i n this respect. entirely differentv from indicators ordinarily referred to as step by step." in which the position of the indicator is dependent upon its previous condition and the mechanism is adapted merely to move it one step at a time.

The rotation of the indicator may be divided into five parts or cycles. each of which is exactly the same and consists in afourstep motion from a position with one rotor pole `piece centered opposite a field magnet j and field magnets C andD with the positive pole piece to a position with the same rotor pole' piece centered opposite t-he next adjacent field magnet pole piece. Assuming that rotor pole piece 2t in Fig. Q 1s sitive and pole piece Q3 negative. the position shown in said figure will be produced by Aconnecting field magnet A with the -negative terminal of a source of electrical energy terminal of said source. rThis will produce two opposite magnetic circuits. one between pole pieces 1st and pole piece 2T. the other between pole pieces 14 and iid'and the pole piece 28. To balance the magnetic field. it,

will he apparent that pole piece 2T must be located exactly opposite pole piece 14a and the pole piece QSniust be exactly midway between the magnetic pole pieces 14 and 14d. v.The larrangement of salient poles 40 is such that a positive location of the rotor l pole pieces is assured because in the normal CII j position it will/be seen that. salient poles f are vlocated adjacent opposite vsides of each` of the energized field magnet pole pieces.

, so that a slight rotation of the rotor in either 4 direction would tend to pull three salient poles' awayvfrom adjacent field magnet pole pieces. an action which, of course. would be strongly resisted.

` To locate'the rotor 1n its nextl position` magnets A. C and D remain energized; and

@magnet B is connected tol the same negative terminal as magnet- A. This will unbalance the magnetic field about pole piece 2T and the rotor, in seeking to regain a balanced position. will move in a clockwise direction This will. of course, tend to unbalance the eld about pole piece 2S. and the rotation will cont-iiiue until the clockwise pull on pole piece 2T exactly balances the counter-clockwise pull on pole piece '28. This position will be attained when the rotor has moved through one quarter of the distance between adjacentfield magnets. In this position. the rotor pole pieces will have magnets' B and C respectively pulling in opposite directions on two salient poles each. while magnets A and D are pulling in opposite directions on three poles each'. leaving one salient pole of each pole-piece projecting beyond magnets A and D. In this position. the forces exerted by the magnetic fields at opposite sides of the rotor exactly balance each other and the rotor will be positively positioned. It will. moreover. be apparent that in this position anv tendency to rotate the rotor will also tend to move three salient poles away from each of t'wo field magnetpole pieces v,and will consequently be strongly resisted. l

The nextstep in the cycle is produced bv disconnecting. field magnet C. leaving :raginets A.. Band D in contact. This produces :i condition exactlysimilar to the first position. except that. the single magnet (D) is .magnet E is connected to the same'positive terminal as magnet D. This produces an unbalanced condition similar to that above.

described in connection with 'the shift `from the normal to the firstpos'ition. and the rotor will be moved through another step` coming to rest with the two left hand salient -poles'of pole piece 2T adjacent pole piece 1i.

and the second. thirdand fourth poles adjacent pole piece 1t". while the opposite rotor pole piece is correspondingly located with three salient poles opposite pole piece latd and two opposite pole pieces 14e. in which position the opposite magnetic fields. each produced by] two adjacent field magnets. bal-` ance each other in their pull on .the -rotor` To complete the cycle. and to turn the rotor to what may be `called itssecond normal po- -sition.`field magnet A is denergized. and

pole piece 2T takes its position centered opposite pole piece l-i" with pole piece QT, syma-nd 1i". This position is exactlythesame .metrically located opposite pole pieces 14 f iso , the same effect can be obtained by net B replaces field magnet A. The number of cycles is dependent only upon the number of field magnets used, it being apparent that- 1f an even number of magnets is utilized,

rangement of the rotor pole pieces so that when one rotor pole piece is exactly opposlte a field magnet pole piece., the opposite rotor pole piece will be symmetrically positioned between two other field magnet pole pleces. This arrangement is not so desirable. however, as the rotor is not symmet1i cal since the p'ole pieces are not diametricallv opposite to each other. 4 u Several other variations in my construct1on may be. made without departing from my lnvention both in the construction and operation of the receiver. It will be obvious. for instance. that more than two rotor magnets and pole pieces may be used.' and that the rotor pole pieces may be constructed of suflcient width so that more than two ad- ]acent magnets may be energized to operate o n asingle pole piece. It is, of course. posslble by this latter system to provide more than four positions in each cycle in which the rotor may be definitely7 located. as the number of methods of unbalancing the magnetic field at opposite sides of the rotor is multiplied. It will also be evident that the number of salient poles may be varied; but in this connection, attention is called to Ithe fact that I have salient poles. This is of particular advantage as it enables me to so arrange the pole pieces that. at all times, 'any movement of the rotor without a change in the'm'agnetic field will tend =to pull three salient poles away from the feldpolepieces. While I have described they salient poles as being located inthe rotor magnet' pole pieces, it will b'eapparent that they may be-forme'd on the field magnet pole pieces; but I con- Sider( the construction disclosed to be pref? erable. i A.

In lthe continuous step by step rotation of the rotor, it'will be noted that each of the. field magnets is-positively energized during seven of s'aidsteps. remains inactive for asucceeding three steps. and then is nega-- tively ven ergized for the subsequent seven steps. In order to have a salient pole adjacent the edge of )a eld magnet ypole piece face during each of the seven steps during` which themagnetis energized. I have' provided seven salient poles: but it will be apparent that while this is desirable it is not a 'necessary arrangement land that a' larger be apparent,\ho'wever.that in any event the' number of poles may be used, particularly if thanumber of field magnets is multiplied andv the-number ofl steps increased. It will equa-l spacing of the field magnet pole pieces i 'and the length of their respective faces makes it desirable to have ali odd number proper arprovided five equally spaced-l shown) which usually surrounds indicators of this type, permitting the'removal of the entlre, u nit wlthout disturbing the base o r electrical connections.^ The rotor is readily removed by simply detaching the spider Sal l from plate l2. Furthermore. the use of large single magnets instead .of coaxial pairs permits the ready replacement of a defective magnet without the disturbance of the' rest of the structure and without substantially deran'ging the indicator. i l y lVhile I Ahave described a specific form of my invent-ion. and ,have indicated certain modifications thereof,it will be apparent that many changes may be ma'de-tl1erein;and I do not consider my invention to be limited to the forms described further than the spirit I of my inventionand thescope of the claims make necessary.

Iclaim: y y y l. In an apparatus for locating element ina plurality ofpositions by .selectiveoperation of magneticI means. a plurality a radially arranged pole piece mounted on 'each field magnet at one end thereof. all of Y a rotating of clrcumferentially mounted field magnetsf.'

ing element, a plurality of magnetic pole.

pieces mounted. on the rotating element. also at one 'eid therof'and lying in said plane, the magnet pole pieces being each provided with a plurality of salient poles. .the distancelbetween adjacent salient poles being an integral component of the vsaid predetermined length.

l2. In anappa'ratus' foi-"locating a rotating ,element in a plurality of positions by selective operation of magnetic means. a plurality of. circumferentially mounted field magnets. L

a radially arranged pole piece mounted on 'i each field magnet, all of said pole pieces bein .located in thev same plane, each of said p0 e pieces having a pole' face of predetermined length, a rotating element. a plurality of magnetic pole pieces mounted on the rotat-l j 'ingr element and lying in saldg plane. the

circumferential length of a magnetic pole piece being a simplemultiple ofthe said predetermined length. the magnetic pole pieces being each provided with a plurality of salient poles, the distance between'adjacent salient poles being an integral component of the'said predetermined length. 3. In an apparatus for locating 'a rotating plurality of equally spaced salient poles formed on the operative face of each of saidv rotating pole pieces, the distance between center lines of adjacent salient poles being equal to one-half the length of the eoperatinz-jr face of a field magnet ,pole piece.

4. In an apparatus for locating a rotating element in a plurality ot positions by selective operation of magnetic means. a plurality of field magnets circumferentially'mounted a radially arranged pole piece on one end of each field magnet. said pole pieces being located in the same plane and each having an inwardly directed arcuate face. said faces being of equal length: and a rotating element mounted centrally between said field magnets and including a plurality of magnets. a

pole piece for each magnetl mounted adjacent an end o the element and having an' outwardly directed face adapted to coperate with the field magnet pole piece faces, said rotating magnet pole piece faces having mounted thereon a plurality of salient poles spaced apart by adistance equal to one half the width of the adjacent face of a field magnet pole piece.

5. In an apparatus for locating a rotating element in a plurality of positions vby selective operation of magnetic means. a pluralityv of circumferentially mounted fieldv magnets. pole pieces mounted on adjacent ends of said magnets. each pole piece having an'inwardly directed face. said faces being of equal length and adjacent faces being spaced by a fdistance equal to said face length. arotor axially arranged with respect to thefieldmagnets. a plurality of magnet pole pieces mounted on -tlie rotor, each of said rotor pole-pieces having an o'dd number of equally spaced salient poles. the construct-ion being such that the energizing of selected field' magnets will accurately locate- ;the rotor magnetpole pieces adjacent certain field magnet pole pieces with said Q salient poles adjacent the outer edges of the .faces of the respective field. magnet pole pieces. v

6. In an apparatus for locatinga rotating element in`A aplurality fpositions by selective o peration'of magnetic means. a plurality of circumferentially mounted field magnets. pole pieces mounted on adjacent ends of said magnets. each pole piece having an inwardly directed face,. said faces being of edges of the faces ofthe respective field magnet pole pieces, v

7. In anapparatus for locating a rotating element in a plurality of positions by selective operationof magnetic means. a mounting plate. a single series ot' fieldmagnets with its p'ole pieces circumferentially mounted on said plate. a rotor axially arranged jwith respect to the field magnets and having one end journaled inthe mounting plate. a plurality of magnets mounted on and revolving with the rotor. pole pieces mounted on ends of the rotor magnets adjacent the mounting plate and adapted to coperate with the field magnet pole'pieces. means carried by one or more of said pole pieces for positioning the rotor in a predetermined position when the field magnets are selectively energized. aramemounted on the ends of plate. and a bearing in .said frame in which the rotor is journaled.

"8. In an apparatus Jfor locating a rotating" element in a plurality otA positions by selective operation of magnetic means. a mounting plate. a-singleseries of field magnets with its pole pieces circumferentially mounted on said plate. a-rotor axially arranged with respect to the field magnets and having one end journaled in the mounting plate. a plurality of magnets mounted on and re- A-volving with the. rotor. pole pieces mounted on ends of the rotor magnets adjacent the' mounting plate and adapted to coperate with the field magnet pole pieces. means carried by one or more of said pole pieces for positioning the rotor in a predetermined position when the field magnets are selectivelyenergized. a lframe mounted von the ends of the field magnets opposite to the mounting llO j the field magnets opposite to the mounting plate. and a shaft carried by the rotor and journaled in said frame.

9. In an apparatus-for locating a rotating -element in a plurality of positions by selective operation of magnetic means. a plurality of cii'cumfereitially mounted field magnets. a pole piece mounted on each field magnet and having an inwardly directed face. the'length of each Jface being the same and being equal to the distance between adjacent pole pieces. a rotating element. a magnet pole piece mounted on said element so as to lie adjacentsaid faces ot' the field pole le i 1,396,893

`pieces during the rotation of the said elerotating pole pieces, the distance between ment. the circumferentlal length of a magadjacent salient poles being an integral comnetpole piece face being equal to three times ponentof the length of a field pole piece 10 the length of each field pole piece face, each face.

5 magnet pole piece being provided with a In testimony whereof I have hereunto set plurality of equally 'spaced salient poles my hand. formed on the operative face of each of said FRANK W. WOOD. 

